High reflectivity micro mirrors are used in optical telecom systems, optical scanners, scientific instrumentation and other applications. These mirrors are used as: 1) scanners which scan an optical beam in a desired pattern, 2) servos which allow the position of an optical light beam to be actively adjusted to maintain optimal positioning on a target, such as an optical fibre or a detector 3) switches which allow optical beams to be switched from one position to another.
At the present time cylindrical crystalline structures of silicon are formed which are referred to as “boules”. These boules are cut into thin membrane silicon wafers which are micromachined until they have a highly reflective surface. U.S. Pat. No. 6,008,128 (Habuka et al) discusses the science involved in smoothing a surface of a silicon wafer until it has a highly reflective surface.
Thin membrane silicon wafers are fragile, temperature sensitive and prone to distortion due to internal stresses which makes the smoothing process more difficult.